I have been trying to read the official docs and guides about how to send message from one device to another. I have saved registration token of both devices in the Real Time Database, thus I have the registration token of another device.
I have tried the following way to send the message
RemoteMessage message = new RemoteMessage.Builder(getRegistrationToken())
.setMessageId(incrementIdAndGet())
.addData("message", "Hello")
.build();
FirebaseMessaging.getInstance().send(message);
However this is not working. The other device doesn't receive any message. I am not even sure, if I can use upstream message sending to conduct device to device communication.
PS: I just want to know if device-to-device messaging is possible using FCM? If yes, then is the code I used have some issue? If yes, then what is the correct way.
Update:
My question was to ask whether device to device messaging without using any separate server other than firebase could messaging is possible or not, if yes than how, since there's no documentation about it. I do not understand what is left to explain here? Anyways I got the answer and will update it as an answer once the question gets reopened.
Firebase has two features to send messages to devices:
the Notifications panel in your Firebase Console allows you to send notifications to specific devices, groups of users, or topics that users subscribed to.
by calling Firebase Cloud Messaging API, you can send messages with whatever targeting strategy you prefer. Calling the FCM API requires access to your Server key, which you should never expose on client devices. That's why you should always run such code on an app server.
The Firebase documentation shows this visually:
Sending messages from one device directly to another device is not supported through the Firebase Cloud Messaging client-side SDKs.
Update: I wrote a blog post detailing how to send notifications between Android devices using Firebase Database, Cloud Messaging and Node.js.
Update 2: You can now also use Cloud Functions for Firebase to send messages securely, without spinning up a server. See this sample use-case to get started. If you don't want to use Cloud Functions, you can run the same logic on any trusted environment you already have, such as your development machine, or a server you control.
Warning There is a very important reason why we don't mention this approach anywhere. This exposes your server key in the APK that
you put on every client device. It can (and thus will) be taken from
there and may lead to abuse of your project. I highly recommend
against taking this approach, except for apps that you only put on
your own devices. – Frank van Puffelen
Ok, so the answer by Frank was correct that Firebase does not natively support device to device messaging. However there's one loophole in that. The Firebase server doesn't identify whether you have send the request from an actual server or are you doing it from your device.
So all you have to do is send a Post Request to Firebase's messaging server along with the Server Key. Just keep this in mind that the server key is not supposed to be on the device, but there's no other option if you want device-to-device messaging using Firebase Messaging.
I am using OkHTTP instead of default way of calling the Rest API. The code is something like this -
public static final String FCM_MESSAGE_URL = "https://fcm.googleapis.com/fcm/send";
OkHttpClient mClient = new OkHttpClient();
public void sendMessage(final JSONArray recipients, final String title, final String body, final String icon, final String message) {
new AsyncTask<String, String, String>() {
#Override
protected String doInBackground(String... params) {
try {
JSONObject root = new JSONObject();
JSONObject notification = new JSONObject();
notification.put("body", body);
notification.put("title", title);
notification.put("icon", icon);
JSONObject data = new JSONObject();
data.put("message", message);
root.put("notification", notification);
root.put("data", data);
root.put("registration_ids", recipients);
String result = postToFCM(root.toString());
Log.d(TAG, "Result: " + result);
return result;
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
try {
JSONObject resultJson = new JSONObject(result);
int success, failure;
success = resultJson.getInt("success");
failure = resultJson.getInt("failure");
Toast.makeText(getCurrentActivity(), "Message Success: " + success + "Message Failed: " + failure, Toast.LENGTH_LONG).show();
} catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getCurrentActivity(), "Message Failed, Unknown error occurred.", Toast.LENGTH_LONG).show();
}
}
}.execute();
}
String postToFCM(String bodyString) throws IOException {
RequestBody body = RequestBody.create(JSON, bodyString);
Request request = new Request.Builder()
.url(FCM_MESSAGE_URL)
.post(body)
.addHeader("Authorization", "key=" + SERVER_KEY)
.build();
Response response = mClient.newCall(request).execute();
return response.body().string();
}
I hope Firebase will come with a better solution in future. But till then, I think this is the only way. The other way would be to send topic message or group messaging. But that was not in the scope of the question.
Update:
The JSONArray is defined like this -
JSONArray regArray = new JSONArray(regIds);
regIds is a String array of registration ids, you want to send this message to. Keep in mind that the registration ids must always be in an array, even if you want it to send to a single recipient.
I have also been using direct device to device gcm messaging in my prototype. It has been working very well. We dont have any server. We exchange GCM reg id using sms/text and then communicate using GCM after that. I am putting here code related to GCM handling
**************Sending GCM Message*************
//Sends gcm message Asynchronously
public class GCM_Sender extends IntentService{
final String API_KEY = "****************************************";
//Empty constructor
public GCM_Sender() {
super("GCM_Sender");
}
//Processes gcm send messages
#Override
protected void onHandleIntent(Intent intent) {
Log.d("Action Service", "GCM_Sender Service Started");
//Get message from intent
String msg = intent.getStringExtra("msg");
msg = "\"" + msg + "\"";
try{
String ControllerRegistrationId = null;
//Check registration id in db
if(RegistrationIdAdapter.getInstance(getApplicationContext()).getRegIds().size() > 0 ) {
String controllerRegIdArray[] = RegistrationIdAdapter.getInstance(getApplicationContext()).getRegIds().get(1);
if(controllerRegIdArray.length>0)
ControllerRegistrationId = controllerRegIdArray[controllerRegIdArray.length-1];
if(!ControllerRegistrationId.equalsIgnoreCase("NULL")){
// 1. URL
URL url = new URL("https://android.googleapis.com/gcm/send");
// 2. Open connection
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
// 3. Specify POST method
urlConnection.setRequestMethod("POST");
// 4. Set the headers
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Authorization", "key=" + API_KEY);
urlConnection.setDoOutput(true);
// 5. Add JSON data into POST request body
JSONObject obj = new JSONObject("{\"time_to_live\": 0,\"delay_while_idle\": true,\"data\":{\"message\":" + msg + "},\"registration_ids\":[" + ControllerRegistrationId + "]}");
// 6. Get connection output stream
OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream());
out.write(obj.toString());
out.close();
// 6. Get the response
int responseCode = urlConnection.getResponseCode();
BufferedReader in = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null){
response.append(inputLine);
}
in.close();
Log.d("GCM getResponseCode:", new Integer(responseCode).toString());
}else{
Log.d("GCM_Sender:","Field REGISTRATION_TABLE is null");
}
}else {
Log.d("GCM_Sender:","There is no Registration ID in DB ,please sync devices");
}
} catch (Exception e) {
e.printStackTrace();
//MessageSender.getInstance().sendMessage(msg, Commands.SMS_MESSAGE);
}
}
//Called when service is no longer alive
#Override
public void onDestroy() {
super.onDestroy();
//Do a log that GCM_Sender service has been destroyed
Log.d("Action Service", "GCM_Sender Service Destroyed");
}
}
**************Receiving GCM Message*************
public class GCM_Receiver extends WakefulBroadcastReceiver {
public static final String RETRY_ACTION ="com.google.android.c2dm.intent.RETRY";
public static final String REGISTRATION ="com.google.android.c2dm.intent.REGISTRATION";
public SharedPreferences preferences;
//Processes Gcm message .
#Override
public void onReceive(Context context, Intent intent) {
ComponentName comp = new ComponentName(context.getPackageName(),
GCMNotificationIntentService.class.getName());
//Start GCMNotificationIntentService to handle gcm message asynchronously
startWakefulService(context, (intent.setComponent(comp)));
setResultCode(Activity.RESULT_OK);
/*//Check if DatabaseService is running .
if(!DatabaseService.isServiceRunning) {
Intent dbService = new Intent(context,DatabaseService.class);
context.startService(dbService);
}*/
//Check if action is RETRY_ACTION ,if it is then do gcm registration again .
if(intent.getAction().equals(RETRY_ACTION)) {
String registrationId = intent.getStringExtra("registration_id");
if(TextUtils.isEmpty(registrationId)){
DeviceRegistrar.getInstance().register(context);
}else {
//Save registration id to prefs .
preferences = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("BLACKBOX_REG_ID",registrationId);
editor.commit();
}
} else if (intent.getAction().equals(REGISTRATION)) {
}
}
}
//Processes gcm messages asynchronously .
public class GCMNotificationIntentService extends IntentService{
public static final int NOTIFICATION_ID = 1;
private NotificationManager mNotificationManager;
String gcmData;
private final String TAG = "GCMNotificationIntentService";
//Constructor with super().
public GCMNotificationIntentService() {
super("GcmIntentService");
}
//Called when startService() is called by its Client .
//Processes gcm messages .
#Override
protected void onHandleIntent(Intent intent) {
Log.d("GCMNotificationIntentService", "GCMNotificationIntentService Started");
Bundle extras = intent.getExtras();
//Get instance of GoogleCloudMessaging .
GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
//Get gcm message type .
String messageType = gcm.getMessageType(intent);
if (!extras.isEmpty()) {
if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR
.equals(messageType)) {
sendNotification("Send error: " + extras.toString());
} else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED
.equals(messageType)) {
sendNotification("Deleted messages on server: "
+ extras.toString());
} else if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE
.equals(messageType)) {
Log.i(TAG, "Completed work # " + SystemClock.elapsedRealtime());
gcmData = extras.getString("message");
Intent actionService = new Intent(getApplicationContext(),Action.class);
actionService.putExtra("data", gcmData);
//start Action service .
startService(actionService);
//Show push notification .
sendNotification("Action: " + gcmData);
//Process received gcmData.
Log.d(TAG,"Received Gcm Message from Controller : " + extras.getString("message"));
}
}
GCM_Receiver.completeWakefulIntent(intent);
}
//Shows notification on device notification bar .
private void sendNotification(String msg) {
mNotificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
Intent notificationIntent = new Intent(this, BlackboxStarter.class);
//Clicking on GCM notification add new layer of app.
notificationIntent.setFlags( Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,notificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
this).setSmallIcon(R.drawable.gcm_cloud)
.setContentTitle("Notification from Controller")
.setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
.setContentText(msg);
mBuilder.setContentIntent(contentIntent);
mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
//Play default notification
try {
Uri notification = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
Ringtone r = RingtoneManager.getRingtone(getApplicationContext(), notification);
r.play();
} catch (Exception e) {
e.printStackTrace();
}
}
//Called when service is no longer be available .
#Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
Log.d("GCMNotificationIntentService", "GCMNotificationIntentService Destroyed");
}
}
According to the new documentation which was updated on October 2, 2018 you must send post request as below
https://fcm.googleapis.com/fcm/send
Content-Type:application/json
Authorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA //Server key
{
"to": "sent device's registration token",
"data": {
"hello": "message from someone",
}
}
To get device's registration token extend FirebaseMessagingService and override onNewToken(String token)
For more info refer to doc https://firebase.google.com/docs/cloud-messaging/android/device-group
I am late but above solutions has helped me to write down this simple answer, you can send your message directly to android devices from android application, here is the simple implementation I have done and it works great for me.
compile android volley library
compile 'com.android.volley:volley:1.0.0'
Just copy paste this simple function ;) and your life will become smooth just like knife in butter. :D
public static void sendPushToSingleInstance(final Context activity, final HashMap dataValue /*your data from the activity*/, final String instanceIdToken /*firebase instance token you will find in documentation that how to get this*/ ) {
final String url = "https://fcm.googleapis.com/fcm/send";
StringRequest myReq = new StringRequest(Request.Method.POST,url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Toast.makeText(activity, "Bingo Success", Toast.LENGTH_SHORT).show();
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(activity, "Oops error", Toast.LENGTH_SHORT).show();
}
}) {
#Override
public byte[] getBody() throws com.android.volley.AuthFailureError {
Map<String, Object> rawParameters = new Hashtable();
rawParameters.put("data", new JSONObject(dataValue));
rawParameters.put("to", instanceIdToken);
return new JSONObject(rawParameters).toString().getBytes();
};
public String getBodyContentType()
{
return "application/json; charset=utf-8";
}
#Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<String, String>();
headers.put("Authorization", "key="+YOUR_LEGACY_SERVER_KEY_FROM_FIREBASE_CONSOLE);
headers.put("Content-Type","application/json");
return headers;
}
};
Volley.newRequestQueue(activity).add(myReq);
}
Note
If you want to send message to topics so you can change parameter instanceIdToken to something like /topics/topicName.
For groups implementation is the same but you just need to take care of parameters. checkout Firebase documentation and you can pass those parameters.
let me know if you face any issue.
I understand that I cannot directly call a future method from a batch class. But from many other answers, I can see that it is possible to do so by creating a helper class and calling the future method there. But it is not working for me. Please check my code below.
Also, I have tried to do it with the queueable class as suggested in this link, but it is not working for me. The error was " Callout not allowed from this future method. Please enable callout by annotating the future method. eg: #Future(callout=true)"
But I am more interested in the first and simpler way to do this.
public class OrdersItemsHelper {
static Document tDoc;
static blob csvBlob;
//prepare csv file to send
public static void CreateCsvFile(List<Order_Line_Items__c> orderItemsList)
{
//Code to create file here
csvBlob = Blob.valueOf(finalstr);
tDoc = new Document();
tDoc.Name = 'sales_items_' +date.today();
tDoc.Type = 'csv';
tDoc.body = csvBlob;
tDoc.FolderId = [select id from folder where name = 'Emarsys Order Files'].Id;
tDoc.ContentType = 'application/vnd.ms-excel';
Insert tDoc;
system.debug('doc inserted');
sendFile();
}
#Future(callout = true)
public static void sendFile()
{
System.debug('I am creating the post request');
Http http = new Http();
HttpRequest request = new HttpRequest();
request.setMethod('POST');
request.setHeader('Authorization','Security Token');
request.setHeader('Accept','text/plain');
request.setHeader('Content-Type', 'text/csv');
request.setHeader('Authorization', 'Bearer ');
request.setBodyAsBlob(csvBlob);
HttpResponse response = http.send(request);
system.debug('response: ' + response);
}
So I tried again by doing it in the queueable apex class. The thing I was missing was "Database.AllowsCallouts" in the class heading. Below is my queueable class which is working with the batch class to send a rest post request.
public class OrderItemFilePostHelper implements System.Queueable,Database.AllowsCallouts
{
private Blob csvBlob;
public EmarsysOrderItemFilePostHelper(Blob csvBlob) {
this.csvBlob = csvBlob;
}
public void execute(System.QueueableContext objContext)
{
System.debug('I am creating the post request');
Http http = new Http();
HttpRequest request = new HttpRequest();
request.setMethod('POST');
request.setHeader('Authorization','Security Token');
request.setHeader('Accept','text/plain');
request.setHeader('Content-Type', 'text/csv');
request.setHeader('Authorization', 'Bearer ');
request.setEndpoint('https://webhook.site/b0746268-e95c-4f94-bcb6-61d4bea54378');
request.setBodyAsBlob(csvBlob);
HttpResponse response = http.send(request);
system.debug('response: ' + response);
}
}
I have a web API project done with .NETCore.
My web API receives a request from another Service A, with the information I have I need to do some conversion on the data and send it to another Service B.
I am expecting that Service B send back some response: like OK or NOK. As the number of codes I can get back from Service B are so much. I would like to know which is the best practices to handle those codes?
As you will see in my code, I get the status code in this way:
var status = (int)response.StatusCode;
And the I have some if to handle this. Looking at my code it looks like a very poor status code Handling but at moment it is the best I can do. I am kindly asking suggestions to improve this.
I am using RestSharp.
Following my code:
[HttpPost]
[Produces("application/json", Type = typeof(MyModel))]
public async Task<IActionResult> Post([FromBody]MyModel myModel)
{
try
{
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
var response = (RestResponse) await _restHelper.GetResponse("ServiceB:url", myModel);
if (response != null)
{
var status = (int)response.StatusCode;
//2xx status OK
if (status >= 200 && status < 300)
{
return Ok(response.Content);
}
//Catch all status code
return StatusCode(status, response.Content);
}
//If for some reason, I don't get any response from ServiceB
return NotFound("No response from ServiceB");
}
catch (Exception ex)
{
_logger.LogError("POST_ERROR", "ServiceB-relay/Post UNEXPECTED ERROR", ex.Message);
return StatusCode(500, "Server error, not able to process your request");
}
}
and this is my restHelper
public class RestHelper: IRestHelper
{
private readonly IConfigurationRoot _config;
public RestHelper(IConfigurationRoot config)
{
_config = config;
}
public async Task<IRestResponse> GetResponse(string configKey, object dtoObject)
{
//Get the URL from the config.json
var url = _config[configKey];
//Create rest client and rest request
var restClient = new RestClient(url);
var request = new RestRequest {Timeout = 30000, Method = Method.POST};
//Add header
request.AddHeader("Accept", "application/json");
//convert the dto object to json
var jsonObject = JsonConvert.SerializeObject(dtoObject.ToString(), Formatting.Indented);
request.AddParameter("application/json", jsonObject, ParameterType.RequestBody);
var taskCompletion = new TaskCompletionSource<IRestResponse>();
//Execute async
restClient.ExecuteAsync(request, r => taskCompletion.SetResult(r));
//await the task to finish
var response = (RestResponse) await taskCompletion.Task;
return response;
}
Thanks
I am doing WEB HTTP calls using Gmail API. Is there a way to batch get message content?
It seems that messages.list only returns messageIds, and messages.get only support single message query.
LIST API: https://www.googleapis.com/gmail/v1/users/userId/messages
GET API: https://www.googleapis.com/gmail/v1/users/userId/messages/id
Help me guys~ Thank you!
You can definitely do batched messages.get(), quite a few questions covering it already:
https://stackoverflow.com/search?q=%5Bgmail-api%5D+batch
The gmail API returns only messageIds first to prevent heavy load.
With those Ids you can get individual full messages or send a batch request for getting a bunch of messages.
After getting the partialMessages(message ids) use this :
List<Messages> fullMessages = getFullyQualifiedMessages(partialMessages);
private List<Message> getFullyQualifiedMessages(List<Message> partialMessages) {
try {
final JsonBatchCallback<Message> callback = new JsonBatchCallback<Message>() {
public void onSuccess(Message message, HttpHeaders responseHeaders) {
fullyQualifiedMessageList.add(message);
}
public void onFailure(GoogleJsonError e, HttpHeaders responseHeaders) {
// do what you want if error occurs
}
};
BatchRequest batch = mService.batch();
for (Message message : partialMessages) {
mService.users().messages().get("me", message.getId()).setFormat("full").queue(batch, callback);
}
batch.execute();
} catch (IOException e) {
e.printStackTrace();
}
Log.d(TAG, "Message" + fullyQualifiedMessageList.size());
return fullyQualifiedMessageList;
}
okay so i have made the basic rest example and now i wanted to take it a step further by using authentication (user login) in my example.
I am only using Java Collection for my data. NO DATABASE !!
I am storeing the user data in a Map where email is the key to his password !!
But i am getting stuck at the basic authentication part where a form request is being posted to my rest -post method where it takes the values from the users...something like this:
#POST
#Produces(MediaType.TEXT_HTML)
#Consumes(MediaType.APPLICATION_FORM_URLENCODED,
public void newUser(
#FormParam("email") String email,
#FormParam("password") String password,#ContextHttpServletResponse servletResponse
) throws IOException {
// Form Processing algo
if(emailexists){
servletResponse.sendRedirect("http://localhost:8080/xxx/LoginFailed.html");
}
else{
servletResponse.sendRedirect("http://localhost:8080/xxx/UserHomPage.html");
}
}
Dont know what i am doing wrong ..
Also only Java Collections are to be used (like Lists,Map.etc).
Am i using the right technique here or anyone has got a better one at their disposel.
Any help would be appreciated !
I am on windows using apache tomcat 6..
AND A TOTAL NOOB AT THIS THING !!
To save persistent data (like usernames and passwords) without a database, you should consider saving the data in a text file server side and reading the data back into a map in your constructor.
However, the more data you have the more expensive this process is. If you have a large number of users you really should consider using databases, because they are more organized, more efficient, and far more easy to use.
#Path("myPath")
public class MyResource {
private static final String FILE_PATH="my/path/to/userdata.txt";
private HashMap<String, String> _userData;
public MyResource() {
try {
Scanner scanner = new Scanner(new File(FILE_PATH));
_userData = new HashMap<String, String>();
while(scanner.hasNext()) {
String[] line = scanner.nextLine().split(",");
_userData.put(line[0].trim(), line[1].trim());
}
} catch(IOException e) {
e.printStackTrace();
}
}
#POST
#Consumes(MediaType.APPLICATION_FORM_URLENCODED)
public Response addNewUser(#FormParam("email") String email,
#FormParam("password") String password)
throws IOException {
PrintWriter writer = new PrintWriter(new File(FILE_PATH));
int statusCode = 200;
// If that email already exists, don't print to file
if(_userData.containsKey(email))
statusCode = 400;
else
writer.println(email + "," + password);
writer.close();
return Response.status(statusCode);
}
}